New Engine.... Part 3 - Cleaning

Its been a while waiting for the new engine to be delivered so I have spent some time cleaning & check all the auxiliaries.

Tinware.

Some of the tin had small amount of surface rust on the paint.

Decided to give them a rub down, Jenolite and a fresh coat of POR-15.

Most of the other tin just required a degrease.

Fuel Injectors Testing

The Brazilian Bosch fuel injectors are like "hen's teeth" and cannot be purchased in Europe or even American markets.

They are solely for South American market. So if you want new ones you will have to take a trip to Brazil.

So given this I deiced to use my old ones. But giving them a good clean and checking.

After a small amount of internet searching I found that the standard injector process is a Flow test bench and a ultrasonic cleaning followed by another flow test.

In my quest to become self reliant and also DIY design & build I set out to build my own test bench.

As my wife comments "Are you getting lost in the detail again" I agreed but could not help myself!

So I needed a reliable method of sending pulses to the injectors (unlike most of the on-line DIY where they just apply a +12V  straight from a sparking connection to a car battery! In Flammable atmosphere!)

I found a suitable generator of pulse on Amazon. Costing only £27. This has 4 modes of operation with different pulse widths and duration. Ideal.

Next comes a system of providing a pressurized fuel supply. I watched many videos and pages. The typical set up uses a fuel pump filter and rail to replicate what is in a car.

Did not want to have to purchased all this additional parts. So I decided that compressed air to pressurize a reservoir of "fuel" which connects to a fuel filter (to remove any particles) a pressure gauge and a suitable connection to the fuel injector.

To find a suitable pressure reservoir - Well after trying a few ideas I found a suitable vessel. The disposable gas cylinders used on a MIG welder. They are pressure vessels for gas and can hold enough fluid.

So first task was to drill a second port on the other end, tap a thread and mount a suitable pressure connector for the exit pipe. I also had to remove the ball valve in the regulator end as I wanted to connect directly without a regulator and use the compressed air regulator instead.

A Brazilian bay fuel filter and my pressure gauge fitted and a couple of isolation valves (to stop having to depressurize between injectors.

Then a length of hosepipe and a jubliee clip to hold the hosepipe to the injector.

Then a decision on the fluid required. Initial I started with a flush of injector cleaner through the system without the injector fitted.

Injector cleaner used:

Filling the unit was hard as I did not fit and extra inlet & valve for the filling so removed the air inlet in the top of the reservoir. So I had some 150ml syringes which I could inject into the air inlet to fill. Had to repeat this 4 times which takes a while.

After the flush and dry air cycle I filled it with the test fluid. I was going to use Petrol but went for Paraffin (kerosene in US) as it is cleaner and will help clean the injectors inside.

Here is a photo of the final setup:

Fitted a injector and when all ready to go. Filled and pressurized to 2 Bar. Drove the injector for 1 minute to flush and then emptied the graduated cylinder.

I decide to record the starting voltage and pressure for each injector and then the volume of fluid injected over a 1 minute duration.

After 1 minute the results where:

Injector 1: 39cc
Injector 2: 39cc
Injector 3: 40cc
Injector 4: 39cc

In conclusion the volumes are all within close levels but there is some slight variation. Also the accuracy of the measuring cylinder needs to be improved as it was only in 2cc volumes.

I was happy to see that there is not a massive difference between them.

As part of the injector testing I looked at the spray pattern.

Managed to capture a few flows using the flash on my phone.

What you will notice is that the spray pattern is more stream than jet.

This was worrying but I thought after a clean it could be improved. However on researching the Brazilian Bosch EV6 injector and its part number.

The specification has a Beta angle of only 5 Degrees which is very narrow.

So the Brazilian uses a very narrow pencil stream injector to spray directly onto the rear of the inlet valve.

Who knew as I was expecting a real misting spray but I suppose 5 degrees is correct and a stream.

Fuel Injectors Cleaning

After the testing the injectors where placed in an Ultrasonic & heated bath with the cleaning solution for 2 hours.

Quick Video of the tank & the amount of gunk that came off them. Yuck!

Fuel Injectors Re-Test

Fitted the cleaned injectors back onto the test bench and repeated the test. The results are as follows:

Injector 1: 40cc
Injector 2: 40cc
Injector 3: 40cc
Injector 4: 40cc

So the clean injectors gave 400 cc/min @ 2 Bar

Not sure how to convert that as it depends on duration of pulse and also the type of fluid and pressure the specification was taken with.

As I was only looking for any issues they are all the same and clean which is good enough for me.

I will do a blog on the type of injectors used and there specifications and maybe alternatives if I find any at a later time.

So all parts are clean and ready. Engine arriving soon (Hopefully).... Stay tuned.

Running Rich - Replacement ECU - Solved!

Running Rich - Solved!

Background

For those that have been following this blog for the last 2 years my Brazilian Kombi has been struggling to get through the yearly MOT.

The issue has always been High CO emissions coming at idle and also at fast RPMs.

After investigating the Lambda sensor is always running at about a constant 0.9v which indicates rich levels. The Lambda sensor should run rich / lean (0.1 to 0.9v) averaging out at about stoichiometric of 0.45v (Lambda=1)

I have checked every sensor and actuator and ran many diagnostic logs all without finding anything wrong. 

I finally concluded that the ECU system was not responding to the rich levels and not adjusting. If you inject more fuel (Propane) or ristrict air the ECU should detect this and adjust its fuel (trim) to aim for 0.45v stoichiometric.

At this level the CO emissions should be at the lowest levels.

My original ECU showed NO SIGNS of attempting to correct anything.

So I have now secured another (used) ECU...... It has travelled a 6800 Mile journey to my Kombi (contact me if you need supplier details)

It an earlier version of the original ECU but its basically the same version.

The Swap

The swap over took half a day. Removal of the old ECU was simple enough (battery & wiring disconnecting and one nut)

I then spent a few hours checking all the 25 connections from the ECU ensuring that each Pin went to the correct place compared to the wiring diagram and that all sensors and actuators where correct.

Then came the replacement ECU which was a simple plug in and secure and then reconnecting the battery.

First Start

Then came the moment of truth. First turn of the key the engine fired up first time and sat at Idle with only a little hunting.

After a few minutes everything settled down. Struggled to restart a 2nd time for unknown reason but after that it was fine.

Hooked up the VCDS Diagnostics (see Diagnostics Guide page on the right) and cleared some old fault codes.

Everything ran fine and the drive was improved. A few fault codes came up about Fuel trims but I assume that this was the ECU "Learning" the engine set-up.

The Results

So after a few longer drives I captured some log files and this is the result:

You can now see the Lambda response switching lean / rich during running.

Also of note is the Fuel Injectors switching basically off during letting off the throttle.This is what I would expect to see from a fully working ECU.

During long periods of idle the injectors period are low and the engine is running rich to lean consistently

RESULT!

Follow Up.

Now I have a functioning spare ECU to use on the bus I can now turn my thought to the orginal ECU. I have been starting an ECU repair manual detailing as much little information on the Bosch Motronic MP9 used on the air-cooled Kombi.

I have been speaking to a ECU repair company and will plan to send of the ECU to them to see what they can find.

I suspect from the repair information I suspect it could be an issue with the supply ground of the Sensor inputs not connecting or floating so it does record the right values BUT not be able to respond. Will keep you all updated on the repair.

I suspect the ECU was always faulty and even more damaged when the Engine Earth lead was found disconnected (see hot start issue)

I am SO happy to have finally resolved the issue. I always suspected it was the engine, timing or sensor wiring issue BUT never suspected the ECU to be at fault. 

I did not want to be a typical parts swapper mechanic condemning ECUs but in this case it was the ECU!

More details and information to follow!

VW Directory / Links page

I have created a new links & directory page which lists companies and sites which supply parts and information related to the Type 2.

Its now available online and is on the pages on the right hand side ->

Here is a link to the page as well.

http://t2bay.blogspot.co.uk/p/vw-t2.html

Hope you all find this information useful. I especially like the reference section as these sites have great information.

Great Parts Diagram Website

I have found a great parts diagram database. Great for most models but the VW section has all diagram which for the Type 2 seem to date back to 1968.

http://www.partsbase.org/vw/

Great for checking parts and also seeing the wonderful diagrams created by VW.